New York — A landmark new estimate of the number of people around the world trapped in modern slavery could galvanise a global drive to end the international crime by 2030, experts said on Tuesday.

At least 40 million people were living as slaves last year in forced labor and forced marriages, found the first joint estimate by key anti-slavery groups of the number of victims.

The International Labour Organization (ILO), human rights group Walk Free Foundation, and International Organization for Migration said 40.3 million people were victims of modern slavery in 2016 - but added this was a conservative estimate.

This marks the first time the anti-slavery organisations have collaborated on an international estimate, which unlike previous numbers also includes people forced into marriages.

The figure sets a baseline for activists and governments in pursuit of the U.N. global goal of ending modern slavery by 2030 - part of the Sustainable Development Goals (SDGs) adopted in 2015 to end poverty, tackle climate change and promote equality.

Here are the views of some leading anti-slavery experts on how the new estimate could influence this international drive:

JACQUELINE JOUDO LARSEN, SENIOR RESEARCH MANAGER, WALK FREE

"A critical first step towards ending modern slavery lies in answering a deceptively simple question - how many people are victims of modern slavery in the world?

The estimate sets a single, albeit conservative, baseline that can guide decisions about the effective targeting of policies, interventions and resources, and against which progress can be measured.

Forty percent of all victims are forced to work in the private economy - producing the food we eat, the clothes we wear, the footballs we kick, and the electronics we buy.

These findings underscore that we all - consumers, the business community, and government - have a responsibility to act on these issues."

KEVIN HYLAND, UK INDEPENDENT ANTI-SLAVERY COMMISSIONER

"Simply put, we cannot fight this crime if we do not understand the true extent and nature of it.

Data which is accurate and reliable is a key weapon for those of us on the frontline of modern slavery.

Along with raising more general awareness, it helps governments and charities to take more strategic decisions and implement policy based on facts rather than guess work.

This can impact many serious aspects of the anti-slavery agenda including law-making and funding.

For too long, we have been making do with out-of-date statistics which fail victims of modern slavery. This new estimate will help to shift policy and attitudes."

KATE GARBERS, MANAGING DIRECTOR, UNSEEN

"With such large numbers being publicised it is fair to assume that very few - if any - nation will be immune to modern slavery.

The challenge now is how to garner universal engagement and agreement of what exploitative practices should be included within the definition of modern slavery, and most importantly how to work together to prevent them from occurring.

We must remain aware of the guises in which slavery can present and link these to other policy and agenda issues, such as migration, business practices, gender, humanitarian crises and victim protection if we are to understand and tackle it."

AIDAN MCQUADE, DIRECTOR, ANTI-SLAVERY INTERNATIONAL

"The big news is that forced marriage has finally been officially recognised as a form of slavery and included in the new slavery estimates.

The treatment of millions of girls who were forced to marry against their will finally be recognised for what it is - slavery, hidden under the guise of marriage.

The toleration of forced marriage, particularly that of children, represents such a fundamental denial of the rights of millions of girls that it provides a fertile ground for the evolution of yet more egregious abuses such as the misogynistic depredations of Boko Haram and Islamic State.

Ending forced marriage is critical to advancing and promoting the rights of women and girls, and hence in ending slavery."

HOLLY BURKHALTER, SENIOR ADVISOR, INTERNATIONAL JUSTICE MISSION

"Today is a landmark day in the fight against modern slavery.

This report is a giant leap forward in helping us to understand how many slaves there are in the world - but the even bigger challenge is not to count slaves, but to free them.

The three groups' willingness to join forces and harmonize definitions and methodologies makes a substantial contribution to implementation of SDG 8.7, which calls for the eradication of forced labour, human trafficking and child labour."

MICHAELLE DE COCK, SENIOR STATISTICIAN, ILO

"Governments, employers, workers' organizations and civil society as a whole should come together to bring an end to modern slavery.

I believe we won't achieve the SDGs unless we dramatically increase our efforts to fight this scourge that affects so many people, especially women and children."

NICK GRONO, CEO, FREEDOM FUND

"This high level focus on data and measurement should encourage governments to do a much better job of measuring slavery in their countries, and responding accordingly.

It will also drive a stronger focus on measurement and impact by those organisations working to end this abuse, and that's to be welcomed."

AllAfrica publishes around 800 reports a day from more than 140 news organizations and over 500 other institutions and individuals, representing a diversity of positions on every topic. We publish news and views ranging from vigorous opponents of governments to government publications and spokespersons. Publishers named above each report are responsible for their own content, which AllAfrica does not have the legal right to edit or correct.

AllAfrica is a voice of, by and about Africa - aggregating, producing and distributing 800 news and information items daily from over 140 African news organizations and our own reporters to an African and global public. We operate from Cape Town, Dakar, Abuja, Monrovia, Nairobi and Washington DC.